Field of the Invention
The present invention relates to a coil component and a circuit board including the same and, more particularly, to a coil component in which magnetic flux leakage to the outside is reduced and a circuit board including the same.
Description of Related Art
A large number of coil components are used in a mobile electronic device such as a smartphone. Along with miniaturization of the mobile electronic device and improvement in performance thereof, the size required of the coil component has been reduced. However, reduction in the size of the coil component involves reduction in the volume of a magnetic member constituting the coil component, with the result that magnetic flux is more likely to leak outside. In addition, when the mounting density becomes high because of miniaturization of each electronic component, the distance between adjacent electronic components is reduced, so that influence of the leakage magnetic flux becomes more prominent.
For example, a coil component described in Japanese Utility Model Application Publication No. H04-076606 has a configuration in which a coil pattern is formed on a green sheet formed of a ferrite magnetic body. In this coil component, a closed magnetic path is formed by the ferrite magnetic body, and thus comparatively less magnetic flux leaks outside. In addition, the size of the coil component is comparatively large (3.6 mm×1.6 mm), so that the volume of a magnetic member constituting the coil component is sufficiently ensured.
However, in recent years, a coil component is required to have a smaller size, which makes it difficult to sufficiently confine magnetic flux in the coil component. In particular, when a low permeability part that segments a part of the magnetic path exists, a large amount of magnetic flux may leak outside from the low permeability part. As described above, such leakage magnetic flux affects other neighboring electronic components more as the mounting density is increased.